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U.S. Department of Labor

Mine Safety and Health Administration
201 12th Street South, Suite 401
Arlington, VA 22202-5450
ISSUE DATE: May 20, 2011
LAST VALIDATED: 03/31/2021


FROM:             KEVIN G. STRICKLIN  
                       Administrator for
                       Coal Mine Safety and Health

                      Administrator for
                      Metal and Nonmetal Mine Safety and Health

                      LINDA F. ZEILER LINDA F. ZEILER
                      Acting Director of Technical Support

SUBJECT:    Run-through Check Curtains

Who needs this information?
Underground coal and underground metal/nonmetal mine operators, miners' representatives, independent contractors, Mine Safety and Health enforcement personnel and other interested parties need this information.

What is the purpose of this Program Information Bulletin (PIB)?
The purpose of this PIB is to inform the mining industry of the hazard associated with opaque, semi-opaque and translucent curtain or fly pads used as a run-through check curtain.

Operators use run-through check curtains to allow mobile equipment to travel to and from a section without having to stop, remove and replace a temporary stopping. These run-through check curtains help prevent short circuiting of air on the section during such travel. Normally, run-through check curtains consist of fly pads of various sizes to accommodate the height and width of the entry opening.

Some mine operators use the semi-opaque yellow or white line curtain with cuts down the sides as run-through check curtains and some mine operators use fly pads that are not transparent.

Only transparent brattice cloth or fly pads should be used as a run-through check curtain since transparent brattice cloth and fly pads transmit the most light from approaching equipment for a miner to see. In addition, for an equipment operator to easily see the check curtain, the use of a transparent brattice cloth or fly pads with reflective strips would be an effective combination to improve safety. A sufficient amount of reflective material should be used to indicate the height and width of the entry or crosscut where the run-through check curtain is located without adversely affecting its transparent properties. Reflective material should be placed on both sides of the curtain. Typically, reflective material is approximately 2 inches in width.

The importance of using transparent run-through check curtain is that it allows equipment operators to see through the curtain to the other side before traveling through. Use audible warning devices prior to running through transparent check curtains as an additional safety measure. Using audible warning devices and transparent check curtains will prevent accidents, injuries and fatalities caused by the equipment operator's visibility being obstructed.

What is the background for this PIB?
MSHA has investigated numerous accidents involving fatalities and lost time injuries resulting from miners being struck by mobile equipment traveling through opaque, semi-opaque and translucent check curtains.

What is MSHA's authority for this PIB?
The Federal Mine Safety and Health Act of 1977 as amended, 30 U.S.C. § 801 et. seq.

Is this PIB on the Internet?
This PIB may be viewed on the internet by accessing MSHA's home page (, choosing "Compliance Info" and "Program Information Bulletins."

Who is the MSHA contact persons for this PIB?
Mine Safety and Health Enforcement
Don Vickers, (202) 693-9760

Technical Support, Approval & Certification Center
Dustin Hinchman, (304) 547-2049

Who will receive this PIB?
Underground Coal Mine Operators
Underground Metal/Nonmetal Mine Operators
Miners' Representatives
Independent Contractors
Line Curtain and Fly Pad Manufacturers